A three dimensional (3D) range camera determines distances to features in a scene that it images and may provide the distances in a range image, also referred to as a 3D image, comprising three spatial coordinates for each of the features relative to an origin of coordinates located at the camera. An active illumination range camera provides range images of scenes that it images responsive to light reflected by features in the scene from light that the camera transmits to illuminate the scene. Typically, an active illumination range camera may illuminate a scene with structured or temporally modulated, optionally infrared (IR), light to acquire a range image of the scene. A range camera that illuminates a scene that it range images with structured light determines distances to features in the scene by triangulation to structures in the structured light that are reflected by the features. A range camera that illuminates a scene that it range images with temporally modulated light, determines round trip times for a temporal “marker” of the modulated light to travel from the camera to features in the scene and back to the camera. The camera, also referred to conventionally as a time of flight (TOF) range camera, uses the round trip time determined for a given feature in the scene and the speed of light to determine a distance to the given feature
Whereas active illumination range cameras were originally relatively scarce and limited to technical, engineering, and scientific applications, active illumination range imaging technology has matured, and range cameras are frequent components of a continually expanding catalog of consumer products. Range cameras may be found not only in video game consoles, but laptop computers, workbooks, tablets, smartphones, and even wrist watches.